Various electric to acoustic transducers (e.g., speakers) and acoustic to electric transducers (e.g., microphones) use a voice coil mounted for axial movement relative to a fixedly mounted magnet assembly. The voice coil is usually fastened to a diaphragm so that they move together enabling the diaphragm to produce or respond to acoustic energy. The voice coil is typically suspended by a resilient mechanism, often referred to as a “spider”, which allows the voice coil to axially move from, and return to, a rest position. It is generally desirable that the spider provide high axial compliance and high radial stiffness.
Voice coil axial movement can be produced by driving an electric current through a voice coil winding. The current is typically sourced from a pair of stationary electric contacts and coupled to terminals on the voice coil by flexible wires. The voice coil movement flexes the wires and, in heavy duty applications, can cause wire fatigue and failure. This problem is of particular concern in the case of miniaturized transducers of the type useful in hearing aids where the winding may be formed of wire having a diameter as small as 0.001 inches.